[MVC 구현하기 2단계] 호이(이건호) 미션 제출합니다. (#525)

app/src/main/java/com/techcourse/DispatcherServlet.java

@@ -6,46 +6,42 @@
 import jakarta.servlet.http.HttpServletResponse;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import webmvc.org.springframework.web.servlet.view.JspView;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerAdapters;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerMappings;
 
 public class DispatcherServlet extends HttpServlet {
 
     private static final long serialVersionUID = 1L;
     private static final Logger log = LoggerFactory.getLogger(DispatcherServlet.class);
 
-    private ManualHandlerMapping manualHandlerMapping;
+    private final HandlerMappings handlerMappings;
+    private final HandlerAdapters handlerAdapters;
 
-    public DispatcherServlet() {
+    public DispatcherServlet(final HandlerMappings handlerMappings, final HandlerAdapters handlerAdapters) {
+        this.handlerMappings = handlerMappings;
+        this.handlerAdapters = handlerAdapters;
     }
 
     @Override
     public void init() {
-        manualHandlerMapping = new ManualHandlerMapping();
-        manualHandlerMapping.initialize();
+        handlerMappings.init();
     }
 
     @Override
-    protected void service(final HttpServletRequest request, final HttpServletResponse response) throws ServletException {
+    protected void service(final HttpServletRequest request, final HttpServletResponse response)
+            throws ServletException {
         final String requestURI = request.getRequestURI();
         log.debug("Method : {}, Request URI : {}", request.getMethod(), requestURI);
 
         try {
-            final var controller = manualHandlerMapping.getHandler(requestURI);
-            final var viewName = controller.execute(request, response);
-            move(viewName, request, response);
+            final Object handler = handlerMappings.getHandler(request);
+            final HandlerAdapter handlerAdapter = handlerAdapters.getHandlerAdapter(handler);
+
+            handlerAdapter.execute(request, response, handler);
         } catch (Throwable e) {
             log.error("Exception : {}", e.getMessage(), e);
             throw new ServletException(e.getMessage());
         }
     }
-
-    private void move(final String viewName, final HttpServletRequest request, final HttpServletResponse response) throws Exception {
-        if (viewName.startsWith(JspView.REDIRECT_PREFIX)) {
-            response.sendRedirect(viewName.substring(JspView.REDIRECT_PREFIX.length()));
-            return;
-        }
-
-        final var requestDispatcher = request.getRequestDispatcher(viewName);
-        requestDispatcher.forward(request, response);
-    }
 }

app/src/main/java/com/techcourse/DispatcherServletInitializer.java

@@ -4,6 +4,11 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import web.org.springframework.web.WebApplicationInitializer;
+import webmvc.org.springframework.web.servlet.mvc.asis.ManualHandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.AnnotationHandlerAdapter;
+import webmvc.org.springframework.web.servlet.mvc.tobe.AnnotationHandlerMapping;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerAdapters;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerMappings;
 
 /**
  * Base class for {@link WebApplicationInitializer}
@@ -17,7 +22,15 @@ public class DispatcherServletInitializer implements WebApplicationInitializer {
 
     @Override
     public void onStartup(final ServletContext servletContext) {
-        final var dispatcherServlet = new DispatcherServlet();
+        final HandlerMappings handlerMappings = new HandlerMappings();
+        handlerMappings.add(new ManualHandlerMapping());
+        handlerMappings.add(new AnnotationHandlerMapping());
+
+        final HandlerAdapters handlerAdapters = new HandlerAdapters();
+        handlerAdapters.add(new ManualHandlerAdapter());
+        handlerAdapters.add(new AnnotationHandlerAdapter());
+
+        final var dispatcherServlet = new DispatcherServlet(handlerMappings, handlerAdapters);
 
         final var registration = servletContext.addServlet(DEFAULT_SERVLET_NAME, dispatcherServlet);
         if (registration == null) {

app/src/main/java/com/techcourse/ManualHandlerMapping.java

@@ -1,35 +1,39 @@
 package com.techcourse;
 
-import com.techcourse.controller.*;
+import com.techcourse.controller.LoginController;
+import com.techcourse.controller.LoginViewController;
+import com.techcourse.controller.LogoutController;
+import jakarta.servlet.http.HttpServletRequest;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
-import webmvc.org.springframework.web.servlet.mvc.asis.ForwardController;
 
 import java.util.HashMap;
 import java.util.Map;
+import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
+import webmvc.org.springframework.web.servlet.mvc.asis.ForwardController;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerMapping;
 
-public class ManualHandlerMapping {
+public class ManualHandlerMapping implements HandlerMapping {
 
     private static final Logger log = LoggerFactory.getLogger(ManualHandlerMapping.class);
 
     private static final Map<String, Controller> controllers = new HashMap<>();
 
+    @Override
     public void initialize() {
         controllers.put("/", new ForwardController("/index.jsp"));
         controllers.put("/login", new LoginController());
         controllers.put("/login/view", new LoginViewController());
         controllers.put("/logout", new LogoutController());
-        controllers.put("/register/view", new RegisterViewController());
-        controllers.put("/register", new RegisterController());
 
         log.info("Initialized Handler Mapping!");
         controllers.keySet()
                 .forEach(path -> log.info("Path : {}, Controller : {}", path, controllers.get(path).getClass()));
     }
 
-    public Controller getHandler(final String requestURI) {
-        log.debug("Request Mapping Uri : {}", requestURI);
-        return controllers.get(requestURI);
+    @Override
+    public Controller getHandler(final HttpServletRequest request) {
+        log.debug("Request Mapping Uri : {}", request.getRequestURI());
+        return controllers.get(request.getRequestURI());
     }
 }

app/src/main/java/com/techcourse/controller/RegisterController.java

@@ -2,20 +2,30 @@
 
 import com.techcourse.domain.User;
 import com.techcourse.repository.InMemoryUserRepository;
+import context.org.springframework.stereotype.Controller;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
-import webmvc.org.springframework.web.servlet.mvc.asis.Controller;
+import web.org.springframework.web.bind.annotation.RequestMapping;
+import web.org.springframework.web.bind.annotation.RequestMethod;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.view.JspView;
 
-public class RegisterController implements Controller {
+@Controller
+public class RegisterController {
 
-    @Override
-    public String execute(final HttpServletRequest req, final HttpServletResponse res) throws Exception {
+    @RequestMapping(value = "/register", method = RequestMethod.POST)
+    public ModelAndView save(HttpServletRequest req, HttpServletResponse res) {
         final var user = new User(2,
                 req.getParameter("account"),
                 req.getParameter("password"),
                 req.getParameter("email"));
         InMemoryUserRepository.save(user);
 
-        return "redirect:/index.jsp";
+        return new ModelAndView(new JspView("/index.jsp"));
+    }
+
+    @RequestMapping(value = "/register", method = RequestMethod.GET)
+    public ModelAndView show(HttpServletRequest req, HttpServletResponse res) {
+        return new ModelAndView(new JspView("/register.jsp"));
     }
 }

app/src/main/webapp/login.jsp

@@ -30,7 +30,7 @@
                                         </form>
                                     </div>
                                     <div class="card-footer text-center py-3">
-                                        <div class="small"><a href="/register/view">아이디가 없나요? 회원가입 하러가기</a></div>
+                                        <div class="small"><a href="/register">아이디가 없나요? 회원가입 하러가기</a></div>
                                     </div>
                                 </div>
                             </div>

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/asis/ManualHandlerAdapter.java

@@ -0,0 +1,28 @@
+package webmvc.org.springframework.web.servlet.mvc.asis;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import webmvc.org.springframework.web.servlet.mvc.tobe.HandlerAdapter;
+import webmvc.org.springframework.web.servlet.view.JspView;
+
+public class ManualHandlerAdapter implements HandlerAdapter {
+
+    @Override
+    public boolean supports(final Object handler) {
+        return handler instanceof Controller;
+    }
+
+    @Override
+    public void execute(final HttpServletRequest request, final HttpServletResponse response, final Object handler)
+            throws Exception {
+        final Controller controller = (Controller) handler;
+        final String viewName = controller.execute(request, response);
+        if (viewName.startsWith(JspView.REDIRECT_PREFIX)) {
+            response.sendRedirect(viewName.substring(JspView.REDIRECT_PREFIX.length()));
+            return;
+        }
+
+        final var requestDispatcher = request.getRequestDispatcher(viewName);
+        requestDispatcher.forward(request, response);
+    }
+}

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/AnnotationHandlerAdapter.java

@@ -0,0 +1,25 @@
+package webmvc.org.springframework.web.servlet.mvc.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+import java.util.Map;
+import webmvc.org.springframework.web.servlet.ModelAndView;
+import webmvc.org.springframework.web.servlet.View;
+
+public class AnnotationHandlerAdapter implements HandlerAdapter {
+
+    @Override
+    public boolean supports(final Object handler) {
+        return handler instanceof HandlerExecution;
+    }
+
+    @Override
+    public void execute(final HttpServletRequest request, final HttpServletResponse response, final Object handler)
+            throws Exception {
+        final HandlerExecution execution = (HandlerExecution) handler;
+        final ModelAndView mav = execution.handle(request, response);
+        final Map<String, Object> model = mav.getModel();
+        final View view = mav.getView();
+        view.render(model, request, response);
+    }
+}

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/AnnotationHandlerMapping.java

@@ -2,21 +2,19 @@
 
 import context.org.springframework.stereotype.Controller;
 import jakarta.servlet.http.HttpServletRequest;
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
-import java.util.Objects;
-import java.util.Set;
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 import org.reflections.Reflections;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
-
-import java.util.HashMap;
-import java.util.Map;
 import web.org.springframework.web.bind.annotation.RequestMapping;
 import web.org.springframework.web.bind.annotation.RequestMethod;
 
-public class AnnotationHandlerMapping {
+public class AnnotationHandlerMapping implements HandlerMapping {
 
     private static final Logger log = LoggerFactory.getLogger(AnnotationHandlerMapping.class);
 
@@ -28,54 +26,48 @@ public AnnotationHandlerMapping(final Object... basePackage) {
         this.handlerExecutions = new HashMap<>();
     }
 
+    @Override
     public void initialize() {
         for (Object subPackage : basePackage) {
-            intTargetPackage(subPackage);
+            initTargetPackage(subPackage);
         }
         log.info("Initialized AnnotationHandlerMapping!");
     }
 
-    private void intTargetPackage(final Object base) {
+    private void initTargetPackage(final Object base) {
         final Reflections reflections = new Reflections(base);
-        final Set<Class<?>> controllers = reflections.getTypesAnnotatedWith(Controller.class);
-        for (Class<?> clazz : controllers) {
-            initTargetController(clazz);
-        }
+        reflections.getTypesAnnotatedWith(Controller.class)
+                .forEach(this::initTargetController);
     }
 
     private void initTargetController(final Class<?> clazz) {
         final Method[] methods = clazz.getMethods();
         for (Method method : methods) {
-            initTargetMethod(clazz, method);
+            initTargetMethod(method);
         }
     }
 
-    private void initTargetMethod(final Class<?> clazz, final Method method) {
-        if (Objects.nonNull(method.getDeclaredAnnotation(RequestMapping.class))) {
-            final HandlerKey key = getHandlerKey(method);
-            final Object instance = getInstance(clazz);
-            final HandlerExecution handlerExecution = new HandlerExecution(instance, method);
-            handlerExecutions.put(key, handlerExecution);
+    private void initTargetMethod(final Method method) {
+        if (method.isAnnotationPresent(RequestMapping.class)) {
+            final List<HandlerKey> keys = getHandlerKeys(method);
+            final HandlerExecution handlerExecution = new HandlerExecution(method);
+
+            final Map<HandlerKey, HandlerExecution> handlerExecutionMap = keys.stream()
+                    .map(key -> Map.entry(key, handlerExecution))
+                    .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
+            handlerExecutions.putAll(handlerExecutionMap);
         }
     }
 
-    private HandlerKey getHandlerKey(final Method method) {
+    private List<HandlerKey> getHandlerKeys(final Method method) {
         final RequestMapping requestMapping = method.getDeclaredAnnotation(RequestMapping.class);
         final String uri = requestMapping.value();
-        final RequestMethod requestMethod = requestMapping.method()[0];
-        return new HandlerKey(uri, requestMethod);
-    }
-
-    private Object getInstance(final Class<?> clazz) {
-        try {
-            final Constructor<?> constructor = clazz.getDeclaredConstructor();
-            constructor.setAccessible(true);
-            return constructor.newInstance();
-        } catch (InstantiationException | IllegalAccessException | InvocationTargetException | NoSuchMethodException e){
-            throw new RuntimeException(e.getMessage());
-        }
+        return Arrays.stream(requestMapping.method())
+                .map(requestMethod -> new HandlerKey(uri, requestMethod))
+                .collect(Collectors.toUnmodifiableList());
     }
 
+    @Override
     public Object getHandler(final HttpServletRequest request) {
         final String requestURI = request.getRequestURI();
         final String method = request.getMethod();

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/HandlerAdapter.java

@@ -0,0 +1,11 @@
+package webmvc.org.springframework.web.servlet.mvc.tobe;
+
+import jakarta.servlet.http.HttpServletRequest;
+import jakarta.servlet.http.HttpServletResponse;
+
+public interface HandlerAdapter {
+
+    boolean supports(Object handler);
+
+    void execute(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception;
+}

mvc/src/main/java/webmvc/org/springframework/web/servlet/mvc/tobe/HandlerAdapters.java

@@ -0,0 +1,20 @@
+package webmvc.org.springframework.web.servlet.mvc.tobe;
+
+import java.util.HashSet;
+import java.util.Set;
+
+public class HandlerAdapters {
+
+    private Set<HandlerAdapter> values = new HashSet<>();
+
+    public void add(final HandlerAdapter handlerAdapter) {
+        values.add(handlerAdapter);
+    }
+
+    public HandlerAdapter getHandlerAdapter(Object handler) {
+        return values.stream()
+                .filter(adapter -> adapter.supports(handler))
+                .findAny()
+                .orElseThrow();
+    }
+}